Storm Warning 29, NWS Juneau, AK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
313 PM AKST Sat Dec 24 2022

.SHORT TERM.../Through Sun night/ Active weather day across the
area as snow starts to diminish in some areas and remains ongoing
in others. Snow reports from over night have ranged anywhere from
2 inches or less to 13 inches across the region. However most
areas have seen amounts in the 4 to 8 inch range.

As of Noon, several of the winter storm warnings have either been
allow to expire or have been cancelled as forecasts for the second
band of precipitation that was supposed to move north this
afternoon and evening have changed. Current thinking has that
second band, which is over the Petersburg, Wrangell, and Kake
areas currently, stalling out in that region and weakening there
through the evening hours. Expect up to 5 inches of additional
snow fall out of that band. Some additional snow from that might
make it into Angoon, Juneau and Hoonah, but by that point the band
should be so weak that snow accumulations will only amount to a
few inches at most. As such the warnings for Juneau, Angoon, and
areas north and west were cancelled. The warnings for Hyder,
Wrangell, Petersburg, and Kake continue with the snow band
basically stalling over top of them this afternoon and evening.

Into Sun, focus now shifts to the next stronger front that is
moving up from the S which will bring another round of
precipitation. However temperatures will have been warming up
since the last band weakened. The rain snow line should be lining
up somewhere in Stephens Passage and south of Angoon by midday
Sunday. Areas north of that can expect another round of snow Sun
afternoon and evening. Fortunately this front is moving rather
quickly so snow amounts will likely be more in the 3 to 6 inch
range through late Sun night for the north. Some winter weather
advisories have been issued as a result.

Winds are the other main factor. Gales continue to blow down Lynn
Canal, and Stephens Passage. and various other parts of the
panhandle are seeing gusty winds up to 45 mph at times. The main
wind generator in the next 36 hours is that strong from coming up
from the south on Sunday. Wide spread gales and even storm force
conditions in the gulf will be the norm as the front comes up.
Lower winds expected in the panhandle though winds of 25 to 30 kt
will be quite common.

.LONG TERM.../Monday through Thursday Night/...The frontal system
will continue to weaken and move away from the Panhandle on
Monday, decreasing winds over the eastern Gulf from around 40 kt
Gale to around Small Craft through Monday evening and winds over
the Inner Channel marine zones decreasing from up to 30 knots
early Monday morning to around 20 knots by the evening. Precipitation
rates and chances will also decrease from south to north over
that same timeframe.

We will have a break between systems on Tuesday with only chances
slight chance to chances of light precipitation and relatively
benign winds for southeast Alaska Winter standards.

Another frontal system approaches the area from the southwest for
Wednesday through Thursday with increased chances for only lighter
precipitation and winds increased from small craft to Gale for the
Outside Waters from Wednesday through Thursday via a tightening
pressure gradient between the frontal system and relatively
higher pressure over northwest Canada. Inner Channel marine winds
look to increase up to low end Small Craft magnitudes starting
early Thursday morning and lasting through the period.

As for temperatures, the milder weather for this time of year
looks to stay around the Panhandle through the period. Highs look
to reach into the low to mid 40s for the southern Panhandle and
into the low to mid 30s for the northern Panhandle. Overnight
lows look to dip into the upper 20s for the northern Panhandle and
into the mid to upper 30s for the southern Panhandle. There as a
steady and gradual cooling trend as we progress through the long
term forecast period. Elevated model forecast 850 mb temperature
advection, weakening through the period, backs this trend
conclusion.

As of this morning, operational weather forecast models were in
good agreement and ensemble member spread was relatively narrow
for this time of year. Therefore, forecast confidence is above
average.

&&

.AVIATION...As the low in the NE Gulf weakens and shifts east the
frontal bands that tracked north and produced variable IFR
conditions dissipate with diminishing sow, improving visibilities
and lifting ceilings for the central and northern areas Saturday
evening. Another low in the SE gulf moves in second round of
precip for southern areas this evening before shearing part later
tonight. Precip will fall more as rain for the south so not
expecting reduced vis/ceilings. The next front Sunday that moves
up from the south will bring increased winds, LLWS, lowering
ceilings and reduced visibility.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Strong Wind from Sunday morning through Sunday afternoon for
     AKZ317-328.
     Strong Wind through Sunday morning for AKZ318.
     Winter Weather Advisory from noon Sunday to 3 AM AKST Monday for
     AKZ318-319.
     Strong Wind through late tonight for AKZ319.
     Winter Weather Advisory from noon to 9 PM AKST Sunday for
     AKZ320>322-325.
     Strong Wind from Sunday morning through Sunday afternoon for
     AKZ323.
     Strong Wind Sunday morning for AKZ325.
     Winter Storm Warning until 9 PM AKST this evening for AKZ326-327.
     Winter Storm Warning until 6 PM AKST this evening for AKZ329.
     Strong Wind through Sunday afternoon for AKZ330-332.
     Winter Storm Warning until 6 AM AKST Sunday for AKZ331.
MARINE...Heavy Freezing Spray Warning for PKZ012.
     Storm Warning for PKZ043-051.
     Gale Warning for PKZ012-013-022-041-042-052.
     Small Craft Advisory for PKZ011-021-031>036-053.

&&

SHORT TERM...EAL
LONG TERM....JLC
AVIATION...PRB

Visit us at http://www.weather.gov/Juneau

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE JUNEAU AK
124 AM AKST SUN DEC 25 2022

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0500 PM     SNOW             17 WSW KAKE             56.85N 134.32W
12/24/2022  M9.0 INCH        PRINCE OF WALES-HYDAK   TRAINED SPOTTER

            TRAINED SPOTTER IN SECURITY BAY MEASURED
            ANOTHER 5.5 INCHES OF SNOW, FOR A NEARLY 2
            DAY STORM TOTAL OF 9 INCHES. STOPPED AT
            ABOUT 5PM SATURDAY AND WAS VERY DRY.

&&

NF

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE JUNEAU AK
154 AM AKST SUN DEC 25 2022

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0900 PM     SNOW             1 SE PETERSBURG         56.80N 132.94W
12/24/2022  M7.8 INCH        PETERSBURG BOROUGH AK   CO-OP OBSERVER

            PETERSBURG COOP AT THE AIRPORT MEASURED 7.8
            INCHES OF SNOW WHICH ENDED AROUND 5PM
            SATURDAY. THE PREVIOUS DAY THEY MEASURED 3.5
            INCHES AND THE SNOW DEPTH IS 11 INCHES.

&&

NF